I should definitely just git gud. However, I feel that - because jump isn't the up arrow and is its own key - I should be able to teleport upwards while holding the right and up arrows. As is, I have to completely let go of the right arrow to teleport up, and it makes everything unnecessarily harder. Ruins the ninja flow.

This is an absolutely phenomenal game, the levels of rage I felt were just on the brink of manageable so you've struck a great balance! The only issue I found was that the frame rate dipped quite a bit in the later levels when things started getting more hectic, it wasn't a gamebreaker though, just a slight annoyance.